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Common Fixes for a Transmission that Jerks or Hesitates

Common Fixes for a Transmission that Jerks or Hesitates

The AMSOIL ATF is one of our best sellers in the Sioux Falls store. Thanks to you many local transmission shops are now suggesting it to their customers. You can pick up here and take to your favorite transmission shop.

Here are a few common reasons why your transmission may shift erratically, jerk or hesitate.

• Low fluid level
• Depleted fluid frictional properties
• Poor cold-temperature fluidity

Start with the easiest fix

There’s an old adage when troubleshooting: start with the least expensive and simplest fix. In this case, check the transmission fluid level first. Low fluid can prevent the transmission from shifting properly. It’s important to find out why the fluid is low and fix any problems. It could be a leaky seal or other mechanical defect. Otherwise, adding new fluid won’t ultimately solve the problem.

Worn fluid equals poor shift quality

Transmission fluid that has aged and lost some of its frictional properties can also lead to poor shift quality. When your vehicle’s computer tells the transmission to shift gears, hydraulic pressure (provided by the fluid) squeezes a series of plates together inside a clutch pack to connect the engine to the transmission output shaft and route power to the wheels. The fluid’s frictional properties play a vital role in ensuring the clutch plates bind together properly and gear shifts occur seamlessly.

Over time, the fluid’s frictional properties can degrade, leading to elongated, jerky or inconsistent shifts. In this case, it’s time for a fluid change.

How do you know for sure the fluid is worn? The only definite way to find out is to conduct used fluid analysis. However, fluid that smells burnt or appears dirty is likely due for a change. It’s best practice to change the fluid before the frictional properties are depleted and you experience poor shifting. Those poor shifts can cause the clutches to wear more rapidly and lead to bigger issues that need mechanical repairs.

Be aware of “adaptive” transmissions

One interesting note affects newer vehicles equipped with adaptive transmissions. These units “learn” your driving habits and the characteristics of the fluid to adjust shifts accordingly. As the fluid loses its frictional properties, the computer compensates and adjusts transmission performance.

** If you’ve recently changed your fluid, the computer may still operate as if old fluid is installed, causing poor shift quality. In these cases, keep driving and eventually the computer will “relearn” your driving habits and the behavior of the new fluid and adjust accordingly. The problem was significant enough on some 2012-2013 Ford F-150s to cause Ford to issue a technical service bulletin (TSB 13-1-10).

What do “frictional properties” look like?

We know what good, crisp shifts feel like. Can we dive in even further and see what they look like?

We can, and they appear as a flat, boring line on a graph. The dark blue line represents the frictional properties of new AMSOIL Signature Series Synthetic Automatic Transmission Fluid. The light blue line shows the frictional properties of the same fluid after more than 180,000 miles in taxi cabs operating in the intense heat of Las Vegas.

As you can see, the lines are extremely close, with no abrupt spikes or dips. This means, after 180,000 miles of severe service, the fluid continued to deliver crisp, confident shifts.

Granted, it’s not exciting to look at – unless you love driving and want to protect your transmission.

Cold weather can reduce shift quality

When the temperature drops, transmission fluids with poor cold-flow properties can thicken and cause elongated and hard shifts until the fluid has warmed up enough to flow properly. Switching to a high-quality synthetic transmission fluid will help. Synthetics don’t contain waxes, as conventional fluids do, meaning they remain fluid at lower temperatures for improved shifts during cold weather.

The best transmission fluid available won’t fix a broken transmission. But using high-quality synthetic fluid can help improve shift quality and maximize transmission life.

Five reasons to use motorcycle oil in your bike

You can use Car Motor Oils in your Bike if you Add Two More Wheels.

You wouldn’t want to buy a used bike if motorcycle oil wasn’t used.

Impressive performance happens when you are using the right oil in the right application.

Len Groom | TECHNICAL PRODUCT MANAGER, POWERSPORTS

The results of a study from lubricant additive manufacturer Infineum caught my eye recently. A survey of 1,000 bikers revealed that fewer than 60 percent are using a motorcycle specific oil in their motorcycles. Interestingly, more than three quarters of respondents think they’re using a motorcycle oil. Clearly there’s confusion in the market that requires clarification.

Let’s start with why you should always use motorcycle oil in a motorcycle engine. I’ll boil it down to five key reasons.

1) Motorcycles run hotter

In general, automotive engines are water-cooled. A typical automotive engine can reach 235ºF (113ºC) during operation, which is plenty hot. Motorcycles, however, run even hotter, particularly big, air-cooled V-twins, like your average Harley Davidson. They rely on air flowing across the engine for cooling, which is inherently less efficient at dissipating heat. This configuration poses additional challenges in stop-and-go traffic when there’s little airflow, particularly on hot summer days. In fact, testing of a 2012 Harley Street Bob in our mechanical lab demonstrated an average cylinder head temp of 383ºF (195ºC).

Heat that intense causes some oils to thin and lose viscosity, which reduces wear protection. High heat also hastens chemical breakdown of the oil (called oxidation), which requires you to change oil more often. In extreme cases, the bike’s temperature sensors can shut down the engine if it gets too hot.

2) High rpm destroys lesser oils

Motorcycles tend to operate at engine speeds significantly higher than automobiles. Your average metric sport bike easily eclipses 10,000 rpm. Some have even pushed 20,000 rpm. Your car or truck’s redline doesn’t even come close. The hydrocarbon chains get ripped to shreds.. You can feel the after-effects through the peg and handle bars.

High rpm places additional stress on engine components, increasing the need for wear protection. It subjects oils to higher loading and shear forces, which can rupture the lubricant film and reduce viscosity, both of which increase wear. High rpm also increases the likelihood of foaming, which can reduce an oil’s load carrying ability, further inviting wear.

3) Increased power density = increased stress

Motorcycle engines produce more horsepower per cubic inch than automobiles. They also tend to operate with higher compression ratios. Increased power density and compression lead to higher engine temperatures and increased stress. This places greater demands on motorcycle oil to fight wear, deposits and chemical breakdown.

4) Must also protect transmission – prevent viscosity loss

Many motorcycles have a common sump supplying oil to both the engine and transmission. In such cases, the oil is required to meet the needs of both the engine and the transmission gears. Transmission gears can shear the oil as it’s squeezed between gear teeth repeatedly at elevated rpm, causing some oils to lose viscosity. Many motorcycles also incorporate a wet clutch within the transmission that uses the same oil. Motorcycle wet clutches require a properly formulated lubricant that meets JASO MA or MA2 frictional requirements.

5) Storage invites corrosion

Whereas automobiles are used almost every day, motorcycle use is usually periodic and, in many cases, seasonal. These extended periods of inactivity place additional stress on motorcycle oils. In these circumstances, rust and acid corrosion protection are of critical concern.

While a good passenger car motor oil (PCMO) hits many of these performance areas, it doesn’t get them all.

PCMOs usually contain friction modifiers to help boost fuel economy. Furthermore, PCMOs don’t meet JASO MA or MA2 requirements. If used in a motorcycle, they can interfere with clutch operation and cause slippage. And no rider wants to deal with a slipping clutch. Likewise, motor oils have no natural rust or corrosion resistance. Instead, corrosion inhibitors must be added to the formulation, and typical motor oils don’t contain them.

AMSOIL Synthetic Motorcycle Oil is designed for the unique demands of motorcycles. It’s formulated without friction modifiers for precise, smooth shifts. It also contains a heavy dose of corrosion inhibitors to protect your engine against rust during storage. And it’s designed to resist viscosity loss due to shear despite intense heat and the mechanical action of gears and chains.

Ensure your customers are using AMSOIL synthetic motorcycle oil in their bikes for the best protection this riding season.

And people who use car oil in their bikes probably use the term “drive” when referring to riding.